1. Field of Invention
The subject invention is generally related to monitoring devices for use in a motor vehicle and is specifically directed to a transfer control apparatus which automatically stops the transfer of fuel from an auxiliary fuel tank to a main fuel tank when the main tank is full.
2. Description of the Prior Art
The trucking industry is an integral part of everyone's life. In 1992, the trucking industry carried approximately 74% of all manufactured goods and accounted for 78% of the freight bill of the United States. Trucks are on the road 24 hours a day, every day of every year, carrying the freight that the nation's consumers and businesses need.
In the field of transport and distribution, good service and timely delivery are vital. As competition increases, the trucking industry continues to search for ways to increase productivity and efficiency. Over the years, truck manufacturers have improved road transport vehicles by making advances in important areas, such as weight reduction and aerodynamics, and by working to provide increased engine power while at the same time reducing the amount of fuel consumed.
While the amounts of fuel consumed have been reduced, large trucks still require considerably more gallons of fuel per mile than an average truck or car. Generally, a large truck will travel only 9 miles per gallon of fuel. In order to avoid frequent stops for refueling, transport trucks are usually equipped with a main fuel tank and a larger storage tank which is connected to the main tank. Typically, a main fuel tank can hold approximately 20 gallons of fuel and a storage fuel tank can hold 60 to 80 gallons. Because the storage tank is large, it is time consuming to fill the tank and is usually only filled once at the beginning of the trip.
In most cases, fuel from the storage tank can be transferred to the main tank while the vehicle is moving by turning a switch in the vehicle which activates a fuel pump. Thus, when the fuel monitor indicates that the gas in the main tank is low, the driver may choose to make a short stop to, refill the main tank or may opt to use the fuel in the storage tank. By activating the fuel pump, the driver can initiate a transfer of fuel from the storage tank to the main tank while in transit and can travel long distances without stopping to refuel. The ability to travel long distances without stopping to refuel may be crucial to making a timely delivery or if there is no place to obtain fuel en route.
While the ability to travel long distances without stopping is crucial, a major: disadvantage with the current practice of transferring fuel while in transit is that the driver is unable to easily determine when the main tank is full. Thus, the driver is unable to determine when the fuel pump should be turned off to stop the: transfer of fuel. If an attempt to monitor the fuel transfer is made, the driver's attention may be diverted from the road and may result in unsafe driving.
Rather than attempting to calculate when a sufficient amount of fuel has been transferred, it is common practice to leave the fuel pump on once it has been activated. However, this is a problem since the volume of fuel in the storage tank greatly exceeds the volume of the main tank. If the driver continues to transfer fuel once the main tank is full, the excess fuel from the storage tank may overflow and may be discharged onto the road or passing vehicles through the gas nozzle receptacle. In addition to wasting fuel and money, the discharge of excess fuel pollutes the environment. Further, loss of fuel which must then be replaced may reduce the efficiency and timeliness of the transport.
Therefore, there is a need for a fuel transfer control apparatus which automatically shuts off the transfer of fuel from the storage tank to the main tank when the main tank is full to prevent undesirable discharge of fuel onto the road or passing vehicle.